This clinical trial is performed with patients with knee osteoarthritis who were radiologically diagnosed with Kellgren-Lawrence (K&L) grade 2 or 3. Subjects who voluntarily signed consent form and met inclusion/exclusion criteria, were evaluated eligible and participated in this trial. Investigator selected knee to be evaluated (right or left) and administered investigational product to selected knee on Day 1.

A total of 3 or 6 subjects will be enrolled in low-dose or mid-dose group each, and 6 subjects will be enrolled in high-dose group. The study used a dose escalation scheme (from low-dose to high-dose) to determine the maximum tolerated dose (MTD).

All subjects in each dose-group will visit 1 month* (visit 5, 1 month±5 days) after administration of investigational product to evaluate dose limit toxicity (DLT) and determine whether to drop or proceed to next dose level.

Total 5 visit (1week, 1 month, 2 months, 3 months, 6 months) until 6 months after administration of investigational product is planned to assess safety through vial sign, laboratory tests, and exploratory efficacy of IP will be assessed through Western Ontario and McMaster Universities osteoarthritis index (WOMAC), 100-mm visual analogue scale (VAS) and International Knee Documentation Committee (IKDC) subjective knee evaluation.

Inclusion Criteria:

1. Male and female over 19 years of age
2. Subject with knee osteoarthritis (OA) and were diagnosed K&L grade 2 or 3 in radioactive examination at time of screening
3. Subject with more than 40mm joint pain on the 100-mm VAS, at the time of screening
4. Subject who were diagnosed as knee osteoarthritis by American College of Rheumatology (ACR) guideline criteria, at the time of screening
5. Subject with Body mass index (BMI) ≤35 kg/m2 at the time of screening
6. Subject with ligament instability ≤Grade II (grade o: no ligament instability, grade I: 0 ~ 5㎜, grade Ⅱ: 5 ~ 10 ㎜, grade Ⅲ: > 10 ㎜) at the time of screening
7. Subject who agree to maintain contraception during study period
8. Subject who voluntarily agreed to participate in the study, and signed informed consent

Exclusion Criteria:

1. Subject with myocardial infarction, congestive heart failure, and other severe heart disease or hypertension (or medical history of hypertension) that are not controlled below 140/90mmHg even with treatment with more than three(3) antihypertensive drugs
2. Subject with serious medical conditions other than cardiovascular disease
3. Subject with, or with a medical history of auto-immune diseases
4. Subject with an infection that requires parenteral antibiotic administration.
5. Subject with a medical history of mental disorder or epilepsy
6. Subject with chronic inflammatory joint diseases such as rheumatoid arthritis (e.g., osteoarthritis with infectious joint disease, gouty arthritis, and osteoarthritis)
7. Subject who had surgery or radiation therapy on knee joint area, or have not recovered from side effects of knee joint surgery within 12 weeks before screening
8. Subject who are pregnant or lactating
9. Subject abuse alcohol 10 times a week or smoke 25 cigarettes a day
10. Subject who were diagnosed with cancer within 5 years before screening
11. Subject who particiapted in another clinical trial within 4 weeks before screening of this clinical trial
12. Subject who were administered with immunosuppressnats such as cyclosporin A or azathioprine within 6 weeks before screening
13. Subject who had intra-articular administration such as sodium hyaluronate injections within 6 month before screening
14. Subject who are suffering from skin disease or considered inappropriate for injection in the injection site
15. Subject who has history of allergic response to hyaluronate injections or DMSO (cryopreservative) or Gentamicin (antibiotics)
16. Subject who are consiered inappropriate for MRI assessment with Tesla higher than 3.0
17. Subject with medical history of cell therapy product administration or are scheduled to administer other cell therapy product
18. Subject who principal investigator (PI) considers inappropriate to participate in the study due to any reasons other than those listed above